Cleaning vehicles

ABSTRACT

A self-propelled sweeper vehicle (10) has front steerable wheels (16) mounted on a centrally pivoted axle assembly (28) which also carries the nozzle (30) and brush gear (24) whereby these assemblies are steered in unison with the vehicle. The nozzle front edge (106) is convex and promotes non-turbulent air intake. The nozzle is formed as a hollow rotationally moulded structure of a plastics material having inherent structural strength and stiffness. The brush gear (24) is mounted on linkages comprising inner and outer portions (200, 202) pivotally connected for folding movement to resiliently yield under impact. The brush covers (260) are formed as hollow plastics mouldings and part of the brush support structure.

This invention relates to cleaning vehicles comprising matter removalmeans such as brush gear or suction gear, or both. An example of such avehicle is a self-propelled cleaning vehicle for cleaning roads and/orrunways and/or pavements and/or carrying out industrial cleaning andsweeping, the vehicle having suction gear including a suction nozzlewith brush gear in the form of side brushes rotating about upwardlyextending axes and serving to sweep matter laterally inwardly into thebath of the nozzle.

Presently available cleaning vehicles require improvement in respect ofthe brush gear and suction gear and associated assemblies, particularlytheir structure, mounting and control. As regards the suction gear,improvements are also needed in respect of the ducts and otherassemblies, particularly their structure and arrangement having regardto air flow, power consumption and related factors.

An object of the invention is to provide cleaning vehicles, and otherapparatus, providing improvements in one or more of these respects, orgenerally.

According to the invention there is provided a cleaning vehicle asdefined in the accompanying claims. The invention also provides otherapparatus as defined in the claims.

The invention also provides cleaning vehicles and other apparatus notlimited by all features of any claim hereof and comprising any novelfeature, or novel combination of features disclosed herein.

Embodiments of the invention will now be described by way of examplewith reference to the accompanying drawings in which:

FIG. 1 shows a perspective view of a cleaning vehicle as seen from thefront and to one side, with the brush gear and suction nozzle turned fora left hand corner;

FIG. 2 shows a perspective view of the vehicle of FIG. 1 as seen fromthe rear and one side, with the vacuum tank shown raised to its reardischarge position for emptying into a skip or the like, the steeringgear and nozzle being shown turned for a right hand corner;

FIG. 3 shows a perspective view from the rear and one side of asuspension assembly forming a front steering unit for the vehicle and asupport for the suction nozzle and brush gear;

FIG. 4 shows, on a larger scale, a vertical section in the front/reardirection through the suction nozzle and associated structures;

FIG. 5 shows a plan view of the left hand half of the nozzle of FIG. 4as viewed in the direction of arrow V in FIG. 4;

FIGS. 6 and 7 show sections through the nozzle of FIG. 5 as indicated byarrows VI - VI and VII--VII in FIG. 5;

FIG. 8 shows a side elevation view of the nozzle in the directionindicated by arrow VIII in FIG. 5;

FIG. 9 shows an end view of the suction duct of FIG. 4, the direction ofviewing being indicated by arrow IX in FIG. 4;

FIGS. 10 and 11 show, diagrammatically, plan views of the vehicle 10during sweeping operations into a right-angled corner, and whenexecuting a left-hand turn, respectively;

FIGS. 12 and 13 show, on a larger scale, one of the brushes of thevehicle of FIG. 1 and details of its mounting, the direction of viewingin FIG. 12 corresponding approximately to that of FIG. 1, and in FIG. 13being indicated by arrow XIII in FIG. 12;

FIG. 14 shows a perspective view of the suction gear including the fanassembly of the vehicle of FIG. 2, the direction of viewing beingindicated, approximately by arrow XIV in FIG. 2, this figure alsoshowing, diagrammatically, the positions and approximate dimensions oftwo plenum chambers, and two vacuum chambers which co-operate with theducts seen in FIG. 14;

FIG. 15 shows an exploded view of one of the fan assemblies seen in FIG.14;

FIG. 16 shows a rear view of part of the vacuum tank assembly of FIG. 2,the direction of viewing being indicated by arrow XVI in FIG. 2;

FIG. 17 shows an assembly of two generally L-shaped cab wall elements;

FIG. 18 shows a side elevation view of frame elements of the driver'scab of the vehicle of FIG. 1;

FIGS. 19, 20 and 21 show sections through a side frame of the cab of thevehicle, the sections being taken in the directions indicated by arrowsXIX--XIX, XX--XX, and XXI--XXI in FIG. 18;

FIG. 22 shows the section of FIG. 21 on a smaller scale together with anassociated sliding window assembly;

FIG. 22 shows a section through a cross-member linking the side framesof the cab, the section being taken in the direction indicated by arrowsXXII--XXII in FIG. 1; and

FIG. 23 shows a vertical section through a modified brush head assembly.

STEERING GEAR

In the case of cleaning vehicles comprising matter removal means such asbrush gear or suction gear or both, problems arise with respect to thesteering arrangements for the vehicle. There are difficulties inmounting the brush gear and/or the inlet or nozzle of the suction gearin order to achieve the most effective cleaning action. This isparticularly so when cleaning around structures such as cars or streetfurniture requiring the vehicle to adopt a turning circle of thesmallest radius possible. Usually cleaning vehicles of this kind arefront steered and this in itself leads to problems in the location ofthe nozzle with respect to the front wheels. The geometry of the wheelmovement in itself means that the nozzle cannot be located directlybetween and closely adjacent to the steered wheels as would bedesirable, since fouling of the nozzle would inevitably occur on tightcorners. Moreover, there is a need to provide a more effective mountingof the brush gear and/or the nozzle with respect to the vehicle as awhole, than is provided by current systems, particularly those in whichthe nozzle assembly is mounted on castor wheels or is mounted on skids.

As shown in the drawings, a cleaning vehicle 10 comprises a vehicle body12 mounted on ground wheels 14 including front steerable wheels 16 anddriven rear wheels 18. Control means 20 in the form of a steering wheeland associated steering gear is provided to control steerable wheels 16in the usual way. Matter removal means 22 comprising brush gear 24 andsuction gear 26 is mounted on vehicle body 12 and is connected tosteerable wheels 16 so as to turn relative to the vehicle body as thevehicle is steered. In this embodiment, the brush gear and the suctiongear are both mounted on support means 28 which is itself mounted forturning movement relative to the vehicle body. The support means alsocarries the steerable wheels 16 so that the entire assembly moves inunison. The matter inlet means or nozzle 30 is located between steerablewheels 16 and closely adjacent to their inner surfaces. The supportmeans 28 has a generally centrally located pivot 32 whereby the assemblycan turn about a generally upwardly extending axis 34. In this way thebrush gear and nozzle and the steerable wheels turn as a singleassembly, whereby their relative positions are unchanged during steeringmovements of the vehicle. A suction duct 36 serving to connect nozzle 30with a chamber or vacuum tank 38 of vehicle 10 is arranged with thelengthwise axis of duct 36 located close to pivot axis 34, the degree ofproximity being such that as the steering assembly turns during vehiclemanoeuvres, the movement of suction duct 36 around axis 34 while joinedat a fixed location at its upper end to vacuum tank 38 produces flexureof duct 36 which can be resiliently accommodated by its flexibility. Ina modification, not illustrated, duct 36 extends through an annularbearing defining steering axis 34.

FIG. 3 shows the general arrangement of support means 28 which is in theform of a unitary front axle unit providing a resilient suspension forthe steerable wheels 16 by virtue of coiled compression springs 76 andassociated shock absorbers 78. The suspension assembly for each of thefront wheels is based upon conventional automotive designs, but isincorporated into the unitary front axle assembly which comprises a mainstructural frame 80 from which a substantial upstanding steering bearing82 projects to be received in bearing housing 150 (see FIG. 4 )projecting down from the vehicle main frame 84 of vehicle 10. Theassembly 28 is connected to the driver's steering wheel and steeringgear box for pivotal movement about steering axis 32. Fixed to mainframe 80 and moving in unison with it are mounting plates 86 to whichbrush gear 24 is secured, as described in detail above.

FIG. 10 illustrates vehicle 10 sweeping out a rectangular corner in amanner which would be impossible for most cleaning vehicles of thiskind. Side sweep brushes 40 and 42 of brush gear 24 are carried on brushmountings 44, 45 comprising swingable support arms 46, 48 for movementin arcs 50, 52 about the axes 54, 56 at the inner ends of the arms,under the control of the driver.

FIG. 10 shows the normal straight ahead positions of the brushes 40, 42,in full lines, and the adjusted positions in dotted lines identified as40a, 40b and 42a, 42b. The brush axes are likewise shown at 58a, 58b and60a, 60b. In FIG. 10, the centre line 62 of vehicle 10 extends throughthe steering axis 32. The maximum angle 64 between the front wheel axesin their straight ahead position and their fully turned position shownin FIG. 1, in this embodiment is 66 degrees.

FIG. 10 clearly shows how, as wheels 16 are turned about axis 34, thebrushes 40, 42 can sweep into the corner defined by building walls 66,68 so that a high proportion of this awkward right-angled zone isthereby swept, by judicious use of the steering and brush swingingcontrols (described below. During the turning movement, the brushes movealong an arc 70 centred on steering axis 34, defining their nominalunadjusted positions. In FIG. 2, corresponding items are numbered as inFIG. 1 and the vehicle is shown being steered around a left-hand benddefined by a curb 72. The problem in sweeping such a bend is illustratedin FIG. 11 by the position of the left-hand brush 42 which is shown inits unadjusted (straight ahead ) position at 42X. Reference 42Y showsthe brush's position after turning the steering about axis 34. Reference42Z shows the corresponding position of the brush after the operator hasactuated the swing control to swing the brush inwards about axis 56 onits support arm 48, whereby the brush reaches curb 72 and thereby has asweep line 74 directing material into the zone of nozzle 30. It will beappreciated that due to the unitary mounting of the brushes and thenozzle, their relative positions during steering manoeuvres (other thanmovement of the brushes about their brush pivot axes ) are the same asif the vehicle were proceeding straight forwards, whereby sweepingefficiency is maintained at all times. The same unitary mounting of thesteerable wheels and the matter removal gear also enables very tightturning circles to be achieved.

Among other modifications which could be made in the above embodimentwithout departing from the scope of the invention are the following.Firstly, for certain applications the vehicle could have rear steerablewheels, or indeed a single steerable wheel. Secondly, the support meansfor the cleaning gear, whether brush gear or suction gear such as anozzle, need not necessarily be in the form of a centre-steer or fifthwheel axle assembly. For example, it is envisaged that the cleaning gearcan be mounted on a pivoted structure connected to a hybrid pivotalackermann type steering system providing differential angular movementfor the steered wheels about individual king pin axes. The supportstructure may have its own upstanding pivotal axis and be connected tothe steered wheels by hydraulic or mechanical means permitting selectivedisconnection (effected when not sweeping ) and providing for greater orequal or lesser angular movement of the cleaning gear than the steeredwheels. Naturally, the invention is applicable to other cleaningmachines such as scrubbing machines and those employing a brush-typematerial lift system in place of a suction system.

SUCTION GEAR--NOZZLE AND SUCTION DUCT

The suction gear 26 of vehicle 10 comprises nozzle 30 connected viasuction duct 36 to a vacuum tank or chamber to receive matter removed inthe cleaning operation. A fan assembly draws the air and entrainedmatter into the tank and discharges its pressure side to atmosphere.

Limitations of existing nozzle and suction duct assemblies includeinadequate air flow efficiency, the production of turbulence,consequential high power consumption in the fan assembly, relativelyhigh manufacturing cost, insufficient ability to accommodate largeforeign bodies such as soft drink cans, and inadequate resistance todamage upon impact with street furniture and the like.

As shown in FIGS. 4 to 9 nozzle 30, constituting matter inlet means, ispositionable in close proximity to a surface 100 to be cleaned. Thenozzle comprises a moulding of a polymeric materialforming a hollowchamber 102 of which the lower surface 104 provides a smoothly profiledupper surface for the front portion of the nozzle. Upper surface 104 ofchamber 102 constitutes an air guide surface. All the internal surfacesof nozzle 30 are smoothly profiled to promote efficient air flow. Asshown in FIG. 5 the front portion 106 of nozzle 30 has a generallyconvex shape as seen in plan view. This shape is made up from a centrallinear section 108 and side sections 110. The result of this convexshape is that the length of the air path over air guide surface 104between the front edge 108, 110 of the nozzle and the rear region 112 ofthe nozzle is of approximately equal length across the full operatingwidth of the nozzle. This is illustrated by the radii 114 shown in FIG.5 and radiating from point 116.

The throat 118 defined by nozzle 30 and into which air and matter aredrawn is defined by air guide surface 104 at the top and by the sweptsurface 100 below. The lateral extend of the throat is defined by sidewalls 120 diverging along radii 114. The throat 118 converges to anozzle outlet 122 to which is joined the lower end 124 of suction duct36. As can be seen in FIG. 5 nozzle outlet 122 and hence lower end 124of duct 36 are of non-circular cross-sectional profile, being generallyrounded and having major and minor axes 126, 128 respectively, thelatter coinciding with the central radius 114 in FIG. 5. Major axis 126extends generally transverse to the direction F of normal forward motionof vehicle 10. It can be seen from FIG. 9 that the upper end 130 of duct36 has a similar cross-sectional profile to its lower end 122, beinggenerally rounded and having a major axis 132 and a minor axis 134. Bothprofiles are thus generally oval or elliptical, thereby serving tocomplement the relatively wide intake width of throat 118 defined byside walls 120, and enabling relatively large objects such as soft drinkcans to pass up the duct 36 without jamming.

As shown in FIGS. 4 to 7 the structure of nozzle 30 is substantiallyentirely a hollow body. Chamber 102 forms the front portion thereof.This is integral with the side walls 120. These latter continue aroundthe rear periphery 136 of the nozzle. As can be seen from FIGS. 4, 6 and7, side walls 120 and the rear peripheral portion 136 have adouble-skinned structure including a generally flat ground-facingsurface 138. At the rear 136 of the nozzle this lower surface 140 isradiused slightly to accommodate raising and lowering of the nozzleabout a lateral axis 142, under the control of the driver to admit largeobjects such as soft drink cans. Hollow chamber 102 and throat sidewalls 120 and rear portion 136 of the nozzle thus form a single hollowstructure having considerable structural strength and impact resistance.These structures are formed of a very durable plastics material. Theunitary nature of the hollow structure of nozzle 36 gives the lattergreat structural integrity. The resilient characteristics of theplastcis material add to this significant impact resistance anddurability. Moreover, the smoothly curved lower profile of rear portion136 of the nozzle complements the corresponding smooth periphery of theforward and internal portions of the nozzle whereby the relatively smallproportion of air entering at the rear of the nozzle does not causeturbulence or otherwise interfere with the smooth air flow.

Nozzle 30 is formed by a rotational or blow moulding technique. Thisenables the hollow structure to be formed in a cost effective manner.Duct 36 is similarly formed. Its lower portion 124 is detachably fixedto the nozzle. Structural integrity is promoted by a flange 144 formedat the bottom of the duct. The duct may be formed in one or morelengths. Its upper end 130 is mounted on a support 146 and is thusfixed. Nozzle 30 turns with front wheels 16 about steering axis 34. Thusduct 36 must accommodate a degree of deflection as steering occurs. Itsmiddle portion moves in an arc around axis 34. The nozzle is mounted onsupport means 28 by fasteners secured to fixing points 148 on thenozzle. The support structure (not shown ) connecting nozzle 30 tosteering axis bearing 150 provides for up and down pivoting of thenozzle about axis 142 under driver control. Such movement isaccommodated by flexure of duct 36. For certain applications, it may bepreferred to manufacture duct 36 from a resilient material such asrubber, suitably reinforced.

In use, the smoothly merging profiles of the nozzle and the suction ductpromote efficient air flow along a principal flow path indicted by line152 in FIG. 4. The air follows a curved path whereby frictional lossesand turbulence are minimized. The generally rectangular oblongcross-sectional shape of throat 118 smoothly merges into the bottom endof suction duct 36, thereby contributing to minimizing air flowefficiency losses. This effect is enhanced by provision of a flaredportion 154 of duct 36 at its upper end 130 where it opens into vacuumtank 38. This flared portion of the suction duct acts as a diffuser inwhich the cross-sectional area of the tube is increased. The kineticenergy of the entrained matter carries it on, but the air is sloweddown. In this way kinetic energy of the air is recovered. For example,with a 10% reduction in air velocity, a 20% reduction in powerconsumption may be achieved.

The provision of the convex front edge of the nozzle has thesignificance that it provides substantially constant path lengths forair entering the nozzle, between the nozzle front edge and the bottom ofthe suction duct, at all positions across the width of the nozzle. Thisgreatly facilitates non-turbulent air intake. The conventionalarrangement with a linear transverse nozzle front edge leads to greatlyvarying lengths of air flow path through the nozzle, whereby theacceleration effect of the nozzle has varying effects on the airaccording to its intake location. Hence, different final air speeds areproduced with consequential turbulence.

Among modifications which could be made in this embodiment withoutdeparting from the scope of the invention are the following. Firstly,the front edge 108 of nozzle 30 could be formed with a curved profileinstead of the approximation thereto provided by the straight edges inthe above embodiment. Considerable variation of the form of the hollowstructure of the nozzle may be needed for particular nozzleapplications. It may be possible to provide a satisfactory nozzle havingtwo or more closed hollow chambers providing structural members thereofand not forming a single continuous chamber. Although the hollow chamberis generally closed, some opening therein for particular applicationsmay be tolerated without significantly affecting structural integrity.Suitable polymeric materials for manufacture of the nozzle and ductassembly include the following, whether with or without suitablefillers: linear medium density polyethylene (LMDPE), linear high densitypolyethylene (LHDPE) ultra high density polyethylene (UHDPE),cross-linked high density polyethylene, Du Pont Hytrel, E.V.A., andothers. Suction duct 36 is oval in section throughout its length. Itcould blend into a larger section cylindrical duct.

SUCTION GEAR--FAN ASSEMBLY AND VACUUM TANK

Previously proposed suction cleaning vehicles employ fans driven bymechanical or hydraulic means from an internal combustion engine. Wherean auxiliary engine is provided to drive the fan, substantial energylosses can be accommodated, but this is not the case with the compactvehicle described below in which a single power plant must drive allsystems of the vehicle and with maximum efficiency. Therefore, in such avehicle, the typical fan operating efficiency of 40% or less forconversion of power imput to air pressure and flow cannot be accepted.Other unsatisfactory aspects of presently available sweeper vehiclesinclude high noise output from the pressure side of the fan and from theentry to the nozzle, and the significant space taken up by air transferducts and chambers and the consequential effect on overall vehicle size.

As shown in FIGS. 2 and 14 to 16 of the drawings, vehicle 10 comprises arear engine 160 driving hydraulic pumps delivering fluid to hydraulicmotors driving rear wheels 18 and corresponding hydraulic motors 162driving respective fan assemblies 164 and 166. The fans constitutesuction means communicating on their suction sides through suction ducts168 and 170 with vacuum tank 38 whereby air and matter are drawn via thenozzle suction duct 36, into the tank. The pressure side of each fandischarges air to atmosphere through respective diffuser ducts 172 and174 which have duct walls which diverge towards the outlet end thereof.The diffuser ducts discharge the air from the pressure side of the fansthrough respective plenum chambers 176 and 178 provided on an upperportion of tank 38 at the front end thereof. The plenum chambers areformed as an integral moulded assembly with two other generallywedge-shaped chambers, namely suction chambers 180, 182. Between plenumchambers 176 and 178 is a central channel 184 having a generallyhorizontal top surface 186 forming a forward continuation of the flatrear surface 188 of vacuum tank 38 which, as shown in FIG. 2, pivots toan open discharge position when tank 38 is raised for emptying. Thevarious chambers and channels are indicated diagrammatically in FIG. 14and are formed in a unitary plastics moulding 190 secured into the topof vacuum tank 38. Suction ducts 168 and 170 open through suctionchambers 180 and 182 and through inclined wire mesh screens 192 intovacuum tank 38. Thus the relatively large rectangular screens constitutethe means through which the tank is evacuated. The arrows 194 indicateair passing through the screens and into the suction ducts. Arrow 196indicates air and entrained matter leaving the discharge end 130 of thenozzle suction tube 36. Arrows 198 show air discharged from the pressureside of fans 164 and 166. the upper ends of diffuser ducts 172 and 174mate with inlet openings 197, 195 formed in plenum chambers 176 and 178.The front and rear walls 193, 191 of the plenum chambers diverge,whereby the fore/aft width of the chambers progressively increases inthe discharge direction. A generally horizontal screen 189, 187 isprovided at the top of each chamber 176, 178 and closes the top openingthereof, extending between the edges defining the opening. The screencomprises wire mesh or expanded metal material and serves further todecelerate air discharged. In use, the plenum chambers represent aconsiderable enlargement of the cross-sectional area of the diffuserducts and serve to decelerate the air discharged into them, and thiseffect is increased by the top screens.

As shown in FIG. 15, fan assembly 166 comprises a bladed impellor 185rotated by hydraulic motor 162 about a lateral axis 183 within a housingformed by an annular duct 181 blending with diffuser duct 174, togetherwith a rear plate 179 and a front plate 177 having a central inletopening connected to suction duct 170. FIG. 15 shows the detail of theduct walls. In FIG. 14, these are shown encased in plastic soundabsorbent material and are not seen so well. The diffuser duct isquadrilateral in cross-sectional shape and generally rectangular. One orboth pairs of the duct walls may diverge. In this embodiment front andrear walls 175, 173 diverge more rapidly than side walls 171, 169. Whereone pair of walls diverges and one pair are parallel, the included anglebetween the diverging walls preferably lies in the range of 5 degrees to20 degrees, and 10 degrees to 12 degrees being the preferred range, with11 degrees the optimum angle. Where all four sides are divergent, theincluded angle between opposite sides may be from 3 degrees to 15degrees, preferably 5 degrees to 8 degrees and ideally 6 degrees. Itwill be noted that fans 164 and 166 are positioned at a relatively lowlocation so that the diffuser ducts 172 and 174 have sufficient lengthfor non-turbulent reduction of air velocity. For example, with a fanoutlet air velocity of about a 130 kilometers per hour it has beenpossible to attain a reduction of air velocity to approximately 8kilometers per hour at the discharge from the plenum chambers, in adistance of about 60 centimeters, in this embodiment. Preferably, adiffuser duct length of at least 30 centimeters is provided.

In use, fans 164, 166 evacuate tank 38 via suction ducts 168, 172 andsuction chambers 180, 182 which are closed at their tops 171, 169 andopen rearwardly through screens 192 into the tank. The pressure drop inthe tank causes air inlet thereto via nozzle 30 and suction duct 36.Entrained matter hits top surface 186 of the tank and is depositedtherein. The pressure sides of the fans discharge through diffuser ducts172, 174 which permit efficient conversion of air kinetic energy topressure and volume flow energy without turbulence, whereby also theefficiency of conversion of fan energy to air flow energy issignificantly enhanced. Efficient deposition of matter within the tankand avoidance of undue dust discharge through the plenum chambers ispromoted by use of a water spray from a water tank 167 to a spraynozzle(not shown) in front of nozzle 30 and discharging directly downwardsonto the surface to be swept. The water thereby collected in tank 38 isrecirculated via a filtering screen, back to the tank. The tank has alower most portion with adjacently downwardly sloping walls from whichportion the recirculated liquid is drawn. The tank includes a separateclean water compartment feeding water to nozzles on the brush gear.

BRUSH GEAR--BRUSH MOUNTING AND CONTROL

In U.S. Pat. No. 4,335,482 (Jones ) there is disclosed a mounting for arotary brush of a sweeper vehicle. The brush is mounted on a leadingarm. The brush can pivot about an axis extending longitudinally of thearm, and about an axis extending transversely of the arm. Both axesextend through the rotation axis of the brush. Shock absorbing means isprovided to reduce bounce of the brush, and to absorb impact loads.Spring means is provided to hold the brush in a defined basic workingposition. In other proporals various control systems are provided tosense and respond to impacts. Nevertheless, the basic vulnerability of aleading arm brush mounting is retained and is protected only accordingto the degree of sophistication and responsiveness of the overload andimpact-detecting control systems associated with it. However, leadingarm brush mountings have considerable advantages with respect to thebasic brushing action, but some improvement in the means for protectingsuch brush mountings from impact and similar loads is needed, which doesnot lead to the complication and expense of previously proposedsophisticated protection and control systems. Likewise, improved andpreferably simplified means for positioning the brush in work and forcontrolling its attitude in work are desirable.

As shown in the drawings, brush gear 24 comprises brushes 40 and 42carried on mountings 44, 45 comprising mounting arms 46 and 48 which arepivotally connected to the steered support means 28 at their inner endsfor pivotal movement about upwardly extending axes 54, 56. The brushmountings extend generally forwardly with respect to direction F. Thebrushes rotate about upwardly extending axes in the direction shown tosweep matter laterally inwardly for collection by nozzle 30. The leftand right arms each comprise inner and outer portions 200 and 202respectively, arranged end to end with pivot means 204 having agenerally upwardly extending pivot axis 206 interconnecting the portions200, 202, whereby the outer portion 202 can turn with respect to theinner portion 202 to permit the brush to yield in a rearward directionby folding movement of the brush mounting, upon impact of the brush withan object.

Inner portion 200 of each mounting arm comprises a parallelogram linkage208 consisting of an upper link 210 and a lower link 212. At their innerends, these links are directly pivoted to support means 28. At theirouter ends, they are likewise directly pivoted to outer arm portion 202.This latter is in the form of an arm and bracket assembly rigidlyfastened to the cover 204 of the respective brush 40, 42. Linkage 208serves to maintain the attitude of outer arm portion 202 whereby thebrush attitude can be controlled. The outer portion 202 is held byresilient means in the form of a spring 216 against a stop 218, therebydefining the normal working positions of the arm portions 200, 202relative to each other. In the normal working position of the brusheswith respect to the fore/aft centre line of the nozzle, assuming thatthe brushes are set for sweeping the normal sweeping width of themachine, the mounting arm inner portions 200 are inclined towards thenozzle centre line at an inclination of about between 5 degrees and 25degrees. The mounting arm outer portions 202 are located on the outboardside of the inner portions and extend laterally and outwardly therefrom.The associated brush is likewise located mainly on the outboard side; ofits inner mounting arm portion. This arrangement, and the geometry ofthe brush mounting assembly generally, is such that a rearward forceacting on the brush due to an impact causes the brush mounting linkageto fold and exert an inwardly-directed force on the inner brush mountingarm portion 200.

In work, spring 216 holds outer arm portion 202 against stop 218.Parallelogram linkage 208 holds outer arm portion 202 at a predeterminedattitude. In this embodiment the pivot joints at the opposite ends ofupper link 200 are universal joints while those at the ends of lowerlink 212 are ball joints, whereby the pivotal movement about verticalaxes 56, 206 as well as the corresponding transverse axes required bythe parallelogram linkage, is permitted. Stop 218 is adjustable todetermine one aspect of the working position of brush 42. In addition,the brush is also adjustable about a brush side loading axis 220 definedby a bolt 222, the position being adjusted by means of adjustment bolts224. Adjustment about axis 220 determines the loading of the brushagainst the swept surface in its main sweeping region which is locatedat the periphery of the brush on the side thereof remote from axis 220.A front/rear adjustment axis 224 permits the loading of the brush to beincreased forwardly or rearwardly in the prime sweeping zone at thefront of the brush. In this embodiment, no provision has been made foradjustment about axis 224, but such can readily be made. Adjustmentabout both axes 220 and 224 could be readily effected by remote control,for example by means of slave hydraulic rams, and/or springs.

Control of the brush gear will now be described. Each brush is driven bya hydraulic motor so as to rotate in direction R. Once the lateralposition of each brush has been set with respect to the front steerablewheels 16, no further lateral adjustment is needed during steeringmanoeuvres, except when some obstacle is encountered or it is desiredto, for example, move one of the brushes outwardly to sweep under anoverhanding building structure. Lateral control of each brush iseffected by means of inner and outer hydraulic rams 226 and 228. Innerram 226 constitutes resilient means. It is supplied with a constant lowpressure source of hydraulic fluid which biases the parallelogramlinkage 208 outwardly. Ram 226 is connected by ball joints 230, 232 atits ends so as to act between support means 28 and lower link 212. Byvirtue of the geometry of the assembly, ram 226 exerts a light liftingforce on the brush, thereby offsetting its weight to an adjustableextent. Outer ram 228 functions as an adjustable stop to limit outwardmovement of the linkage. In use, when the linkage is to be movedoutwards, the driver operates a valve to connect outer ram 228 to tankwhereby it can retract under the outward force of inner ram 226 and/orthe reaction force of the brush against the road surface. When the brushhas reached the desired position, the driver isolates ram 228 and itthen acts as a stop and holds the linkage in its new position relativeto support means 28. To move the brush to its central transport positionor to move it inwards, outer ram 228 is pressurised. During normal workthis action defeats the relatively low hydraulic pressure supplied toinner ram 226 and the brush moves inwards in contact with the surfacebeing swept. If the brush is to be raised, inner ram 226 is alsopressurised, thereby also raising the linkage as it moves inwards.

When the brush hits an obstacle, it first swings rearwards about axis206 while generating a laterally inward force on linkage 208 whichovercomes the light outward bias from ram 226 and permits the brush alsoto swing inwards as well as rearwards. A relief or pressure controlvalve connected to ram 226 may permit it to discharge to tank underthese conditions. Alternatively, according to the setting of the reliefvalve, ram 226 may cause the linkage to rise thereby providing a thirdmode of relief movement of the brush. At the same time outer ram 228resiliently resists the lateral inward movement of the linkage bydevelopment of a partial vacuum within the ram. Thus, outer ram 228 ismainly a stop device which also functions as a swing actuator and underimpact provides resilient resistance. Inner ram 226 functions mainly asa resilient device loading the linkage outwards but which also has liftfunctions and overload relief functions under impact conditions. Ram 228acts through ball joints 234 and 236 between support means 28 and upperlink 210.

Amongst other modifications which could be made in the above embodimentare alternative resilient devices in place of those provided,alternative pivot joint constructions and attitude adjustment means, andgeneral modifications to the geometry of the assembly. The two singleacting rams could be replaced by a single double-acting ram.

BRUSH MOUNTING--BRUSH COVERS

In the case of matter removal means such as brush gear of a cleaningvehicle it is found that the brush heads are vulnerable to damage,particularly in the case of those mounted on leading arms. Usually,these structures carry drives such as hydraulic motors together withspray nozzles, together with the linkage for supporting the brush head.All these structures are vulnerable to damage upon impact with fixedobject such as street furniture. Previous proposals for meeting theserequirements, such as freely rotatable impact plates, have not beenfound to be adequate, and improvements are required in respect ofreduced vulnerability and/or reducing the height requirements of thebrush assembly so that the latter can sweep under certain items ofstreet furniture such as seats and the like.

FIG. 23 shows details of brush-supporting covers of FIG. 1. FIGS. 12 and13 show different brush gear supports. As shown in FIG. 23 brush 42comprises bristles 250 mounted on a carrier plate 252 coupled to theoutput shaft 254 of hydraulic motor 256 driven through hose couplings258 to effect rotation about axis 260. The motor is located in a housing260 forming a brush cover and serving to house motor 256 together withspray nozzles 262 located at circumferentally spaced positions along thefront periphery of housing 260 to spray water in an arc indicated byline 263 on the forward side of the cone described by bristles 250.Nozzles 262 receive water from the clean water compartment of tank 167.

Housing 260 forms part of the mounting structure for brush 42 and is inthe form of a hollow body forming part of the load bearing supportstructure of the brush. The housing has connection means 264 for directload-bearing connection to the brush mounting linkage. In thisembodiment, the outer portion 202 of the brush mounting arm is rigidlysecured to connection means 264, and the latter structurally integralwith housing 250, which is formed as a single hollow structure of asuitable plastics material, and serves as a flexible and resilientimpact device for collisions of the brush assembly with street furnituresuch as seats and lamp posts. The hollow plastic structure has internalmetal support elements 266 which are directly coupled to the brushmounting linkage. These serve to transfer the brush support loads to thehollow plastics body 260. However, the major portion of the strength andrigidity of the housing 260 is derived from its own plastics materialand the hollow form thereof. The internal metallic structure 266 may bebonded thereto. Openings may be formed in the hollow body sufficient foradmission and removal of the motor 256 and its hoses. It will be notedthat the brush mounting arm connected to brush 42 extends generallyhorizontally thereto, and preferably does not project above same by morethan about 2.5 centimetres.

In use, housing 260 serves to protect motor 256 and nozzles 262 fromdamage by impacts with fixed objects. The housing adds almost nothing tothe overall height of the brush assembly and permits connection of thebrush mounting linkage directly to it. Its hollow form gives itsignificant structural strength whereby the plastics material hassufficient rigidity while retaining the inherent impact resistance ofsuch material, whereby the vulnerability of the brush assembly isgreatly reduced.

The materials for the construction of housing 260 may be the samesynthetic polymers as those for the nozzle 30.

VEHICLE CAB

In conventional cab arrangements for cleaning vehciles, and many othertypes of vehicles, the general mode of construction is by use offabrication techniques involving the use of hundreds of different partseach requiring its own manufacturing process. The result is that the cabis relatively complex and expensive, and is thus in need of considerablesimplification and cost reduction.

In this embodiment, a driver's cab for a cleaning vehicle has a frameand wall means mounted on the frame. The frame comprises a pair oflaterally spaced structural side frames, and the wall means extendslaterally between the side frames and comprises at least one integralmoulding of plastics material forming at least part of at least twoadjacent walls of the cab, such as the floor and the rear wall. Theframe comprises a hollow section having at least one and preferably twoflanges. A wall portion of the hollow section is disposed at less than90 degrees with respect to an adjacent wall portion, whereby theobstruction of vision provided by the section in critical vision areasof the cab, such as the front left and right lower side portions, isreduced. The hollow section comprises extruded aluminium. Two structuralside frames are linked by cross frame members. The hollow sectionprovides an angled profile to seat a complementary flange of the plasticwall portion of the cab. The frame section is formed by pulltrusion, orany other suitable forming operation. The flanges are disposed generallyat right angles to each other. In use, the frame elements are slightlyseparated and then allowed to snap back into position to hold the cabwall elements in place. By this construction, the number of individualparts for the cab is very greatly reduced. The frame is relatively cheapto produce. The cab wall elements are likewise relatively inexpensivedue to production by vacuum forming, or other simple forming techniquessuch as rotational moulding, blow moulding or the like. The sidesurfaces of the cab providing the door and windows may be formed fromsuitable section aluminium extrusions having provision for glass supportpurposes. A single door may be provided at one side only of the cab,with the other side having a fixed door / wall unit. The door unit maybe hinged or arranged to slide for opening purposes. The cab wallelements may be formed in a suitable transparent plastics material suchas polycarbonate, whereby visual inspection of the brush gear below thecab can be achieved in use. It is believed that the cab construction maywell be suited to many other types of vehicles, including tractors andboth off-highway and road vehicles.

As shown in FIGS. 1, 2 and 17 to 22, cab 300 of vehicle 10 is mounted onthe frame 84 of the vehicle through resilient mounts (not shown ). Thecab comprises a frame 301 having mounted thereon wall means 302 in theform of two integral plastic mouldings 304, 306, each forming part of atleast two adjacent walls of the cab. Details of the structure of the cabwall means are shown in FIG. 17. Each of the plastic mouldings 304, 306is generally L-shaped. Moulding 304 provides the base or floor portion308 of the cab, together with a major part of the rear wall 310. A joinline 312 defines the adjacent edges of the two plastic mouldings.Moulding 306 provides the cab roof 314, and the remaining portion 316 ofthe rear wall. The two wall portions 304 and 306 are rivetted or bondedto the frame 301 in a very straightforward manner, whereby cabconstruction is greatly simplified. It will be noted that moulding 304provides a base 318 for the driver's seat. This requires merely theaddition of suitable resilient material to constitute an acceptableseat. Likewise, a moulded back rest 320 also merely requires similarresilient material. Alternatively, a conventional vehicle seat may besecured to these structures. Laborious multiple fabrication operationshave been greatly reduced, and in fact almost eliminated.

Referring now to FIGS. 18 to 22 showing details of the cab framearrangement, two integral side frame members 322 are provided. Each isformed as a welded assembly of an extruded aluminium section seen inFIGS. 19 to 22. The aluminium section 324 has flanges 326 and 328disposed as shown. Flange 328 provides a support for the cab roof 314,which is secured by rivets 330. Suitable resilient sealing strips (notshown ) are provided on the flanges 326, 328 to ensure water tightjoints. Flange 326 lies in a generally vertical plane all round the sideframe members and serves to support the cab window assembly designatedin general by reference numeral 332. The floor 308 of the cab is formedwith a sloping side flange 334 at its edges. Similar flanges are formedon the cab back wall portions. These flanges co-operate with a profiledwall portion 336 of the hollow section 324, as shown in FIG. 21. Theflange 328 serves as a retaining stop. The same wall portion 336co-operates with a corresponding flange 338 of a polycarbonate rear viewwindow portion seen in FIGS. 19 and 14, but not indicated in FIG. 17.Frame 301 comprises cross members to provide lateral stiffening, theseincluding the section 340 seen in FIG. 22 and having a flange 342 toco-operate with the flange 334 at the front edge of the cab base wall308. Similar transverse stiffeners are provided at each corner of thecab. FIG. 18 shows the positions in the cab of the steering gear box 344and a driver's control panel 346. The absence of any undercuts in themoulded plastic assemblies 304, 306 enables these to be producedrelatively rapidly and economically by vacuum forming techniques.

I claim:
 1. A cleaning vehicle comprisinga rigid self-propelled vehiclebody; ground wheels to support said vehicle body and including one ormore steerable wheels mounted for steering movement relative to theadjacent structure of said vehicle body; control means to control saidsteerable wheels; matter removal means positionable in working relationto a surface to be cleaned to remove matter therefrom, said matterremoval means comprising a brush and a matter inlet suction nozzle; saidbrush being pivotally mounted on said vehicle body for lateral movementinwards and outwards relative to the travel direction of the vehicleabout an axis relative to the adjacent structure of said vehicle bodyduring said use; and in addition to said pivotal mounting of said brushon said vehicle body, support means for said brush and for said matterinlet nozzle permitting additional pivotal movement of said brush andpermitting pivotal movement of said inlet nozzle relative to theadjacent structure of said vehicle body, the axes of said pivotalmovement and of said additional pivotal movement of said brush beingspaced apart, and said control means to control said steerable wheelsbeing directly connected to both said brush and to said inlet nozzle toeffect said additional pivotal movement of said brush and said pivotalmovement of said inlet nozzle relative to the adjacent structure of saidvehicle body and in synchronism with and in the same sense as thesteering movement of said steerable wheels.
 2. A cleaning vehicleaccording to claim 1 further characterized in that said ground wheelsinclude at least one driven wheel whereby said vehicle isself-propelled, a prime mover being provided to drive said driven wheel,and said matter removal means comprising suction gear including achamber to receive matter removed in a cleaning operation, said matterinlet nozzle being positionable in close proximity to said surface to becleaned to remove matter therefrom, a duct connecting said chamber andsaid matter inlet nozzle, and suction means being in communication withsaid chamber to draw air and matter through said matter inlet nozzle andthrough said duct into said chamber, said support means comprisingstructure mounted on said vehicle body for pivotal movement about anupwardly extending axis relative thereto and connected to said steerablewheels for steering movement in synchronism with and in the same senseas said steerable wheels.
 3. A cleaning vehicle according to claim 1further characterized in that a further brush is similarly mounted toeffect said additional pivotal movement in synchronism with said onebrush, and said matter inlet nozzle is positioned to receive matterswept inwards by contra-rotation of the brushes, and said matter inletnozzle is maintained in proper relationship to both said brushes throughsaid pivotal movement and under the control of said control means.
 4. Acleaning vehicle according to claim 1 further characterized in that saidbrush and at least one of said steerable wheels are mounted on saidsupport means.
 5. A cleaning vehicle according to claim 4 furthercharacterized in that said support means comprises a frame carrying bothsaid steerable wheels and mounted for pivotal movement about an axislocated between said steerable wheels.
 6. A cleaning vehicle accordingto claim 5 further characterized by a duct connected to said matterinlet nozzle to supply suction thereto, said duct extending generallyupwardly from said matter inlet nozzle and being located close to theaxis about which said support frame turns.
 7. A cleaning vehiclecomprising:a rigid self-propelled vehicle body; ground wheels to supportsaid vehicle body and including one or more steerable wheels mounted forsteering movement relative to the adjacent structure of said vehiclebody; control means to control said steerable wheels; matter removalmeans positionable in working relation to a surface to be cleaned toremove matter therefrom, said matter removal means comprising a brushand a matter inlet suction nozzle positionable in close proximity to thesurface to be cleaned; said brush being pivotally mounted on saidvehicle body for lateral movement inwards and outwards relative to thetravel direction of the vehicle about an axis relative to the adjacentstructure of said vehicle body during said use; a chamber carried bysaid vehicle body to receive matter removed by said matter removal meansin a cleaning operation; a duct connecting said chamber with said inletnozzle; and suction means in communication with said chamber to draw airand matter through said matter inlet nozzle and through said duct andinto said chamber; said matter inlet nozzle having a smooth internalprofile and said nozzle including as a structural part thereof amoulding made of a polymeric material and in the form of a hollowchamber, the lower surface of which moulding provides part of saidsmooth internal profile; said hollow chamber being disposed so that saidlower surface of said moulding directly overlies the surface being sweptduring use; and said lower surface of said moulding having a convexprofile which, as seen in cross-section taken in the travel direction,smoothly merges with a curved lower portion of said duct.
 8. A cleaningvehicle comprising:a rigid self-propelled vehicle body; ground wheels tosupport said vehicle body and including one or more steerable wheelsmounted for steering movement relative to the adjacent structure of saidvehicle body; control means to control said steerable wheels; matterremoval means positionable in working relation to a surface to becleaned to remove matter therefrom, said matter removal means comprisinga brush and a matter inlet suction nozzle positionable in closeproximity to the surface to be cleaned; said brush being pivotallymounted on said vehicle body for lateral movement inwards and outwardsrelative to the travel direction of the vehicle about an axis relativeto the adjacent structure of said vehicle body during said use; achamber carried by said vehicle body to receive matter removed by saidmatter removal means in a cleaning operation; a duct connecting saidchamber with said inlet nozzle; and suction means in communication withsaid chamber to draw air and matter through the matter inlet nozzle andthrough said duct and into said chamber; the front portion of said inletnozzle being generally convex as seen in plan view so that the air pathunder said front edge of said inlet nozzle to the rear region of thelatter which connects same to said duct is of approximately equal lengthacross the full operating width of the inlet nozzle; the forward portionof said inlet nozzle which directly overlies the surface being swept,and which has a smoothly profiled downwardly facing convex lower airguide surface, extends lengthwise of the inlet nozzle in the traveldirection throughout a substantial portion of the overall dimension ofthe inlet nozzle measured in said travel direction, and throughout itslengthwise extent overlies directly the surface being swept and definestherewith a forwardly facing and rearwardly tapering throat in whichmatter is entrained in the air flow.
 9. A cleaning vehicle according toclaim 8 characterized in that said matter inlet nozzle has a smoothinternal profile with rounded contours, and said duct connecting saidchamber to said matter inlet nozzle extends upwardly from said matterinlet nozzle which is adjacent said surface to be cleaned to a dischargelocation in said chamber, the cross-sectional profile of said ductsmoothly merging with that of said matter inlet nozzle, and said ductbeing of not-circular cross-sectional profile throughout a substantialportion of its length up to and including its discharge end, the ductbeing generally rounded in profile and having major and minor axes, themajor axis extending generally transverse to the direction of normalforward motion of said vehicle.
 10. A cleaning vehicle according toclaim 9 characterized in that said duct comprises an outwardly flaredportion at its discharge end.
 11. A cleaning vehicle comprising:a rigidself-propelled vehicle body; ground wheels to support said vehicle bodyand including one or more steerable wheels mounted for steering movementrelative to the adjacent structure of said vehicle body; control meansto control said steerable wheels; matter removal means positionable inworking relation to a surface to be cleaned to remove matter therefrom,said matter removal means comprising a brush and a matter inlet suctionnozzle; said brush being pivotally mounted on said vehicle body forlateral movement inwards and outward relative to the travel direction ofthe vehicle about an axis relative to the adjacent structure of saidvehicle body during said use; and said brush being rotatable about anupwardly extending rotational axis and carried on a brush mounting armassembly extending generally forwardly with respect to the normaldirection of operative forward motion of said vehicle, to sweep matterlaterally with respect to said direction, said brush mounting armassembly comprising inner and outer arm portions connected by pivotmeans having a generally upwardly extending pivot axis interconnectingsaid portions, the relative dispositions of said brush mounting armportions with respect to the travel direction in their normal in-usepositions being such that said inner brush mounting arm portion normallyextends generally forwardly with respect to the travel direction andsaid outer brush mounting arm portion extends generally laterallyoutwardly therefrom with respect to the center line of the vehicle,whereby on impact of said brush with a foreign body, the outer brushmounting arm portion can pivot with respect to said inner arm portion topermit the brush to yield in a rearward direction by folding movement ofthe brush mounting arm assembly.
 12. A cleaning vehicle according toclaim 11 characterized in that said inner brush mounting arm portioncomprises upper and lower links forming a parallelogram linkage, andsaid pivot means connecting said inner and outer brush mounting armportions permits pivotal movement of said outer brush mounting armportion about said upwardly extending pivot axis until it engages a stopdefining the normal working attitude of the outer brush mounting armportion with respect to the inner brush mounting arm portion, andresilient means being provided to hold the brush in said normal workingposition.
 13. A cleaning vehicle according to claim 12 characterized inthat said brush is also position-adjustable about at least one furtheraxis, said further axis lying in a generally horizontal plane.
 14. Acleaning vehicle according to claim 12 characterized in that said brushis position-adjustable about two further axes lying in a generallyhorizontal plane, one axis extending generally in the travel direction,and the other axis extending generally laterally with respect thereto.15. A cleaning vehicle comprising:a rigid self-propelled vehicle body;ground wheels to support said vehicle body and including one or moresteerable wheels mounted for steering movement relative to the adjacentstructure of said vehicle body; control means to control said steerablewheels; matter removal means positionable in working relation to asurface to be cleaned to remove matter therefrom, said matter removalmeans comprising brush gear and a matter inlet suction; said brush gearbeing carried by said vehicle body and comprising a brush rotatableabout an upwardly extending axis and carried on a brush mountingextending generally forwardly with respect to the normal direction ofoperative forward motion of said vehicle to sweep matter laterally withrespect to said direction; said brush mounting being connected to saidvehicle body for pivotal movement about a generally upwardly extendingaxis for lateral movement towards and away from a center line of thevehicle; actuating means connected to said brush mounting and acting tobias said mounting outwards with respect to said center line and towardsa working position of said brush; adjustable stop means under remotecontrol from a driver of said vehicle, the stop means being connected tosaid mounting to define a position at which said mounting stops in saidoutward movement; and actuating means under driver control to returnsaid mounting towards said vehicle center line.
 16. A cleaning vehicleaccording to claim 15 characterized in that said adjustable stop meansand said actuating means under driver control to return said mountingtowards the vehicle center line are provided by a pressure operated ram.17. A cleaning vehicle according to claim 15 characterized in that aportion of a driver's cab of said vehicle is provided with transparentmaterial whereby visual inspection of the position of said brush gearbelow the cab during use can be achieved for the purpose of manuallysetting said stop means.
 18. A cleaning vehicle according to claim 15characterized in that said actuating means connected to said brushmounting comprises a pressure operated ram connected to a controlcircuit which normally provides the ram with a pressure supplysufficient to achieve outward movement of said brush mounting, saidcontrol circuit permitting pressure relief under conditions of overloadsuch as an impact of the brush gear with an obstacle.
 19. A cleaningvehicle comprising:a rigid self-propelling vehicle body: ground wheelsto support said vehicle body and including one or more steerable wheelsmounted for steering movement relative to the adjacent structure of saidvehicle body; control means to control said steerable wheels; matterremoval means positionable in working relation to a surface to becleaned to remove matter therefrom, said matter removal means comprisingbrush gear and a matter inlet suction nozzle; said brush gear beingpivotally mounted on said vehicle body for lateral movement inwards andoutwards relative to the travel direction of the vehicle about an axisrelative to the adjacent structure of said vehicle body during use; achamber carried by said vehicle body to receive matter removed by saidmatter removal means in a cleaning operation; a duct connecting saidchamber with said inlet nozzle; and suction means having its suctionside connected to said chamber through screening means to draw air fromsaid chamber thereby lowering the pressure therein and causing air andmatter to be drawn through said inlet nozzle and through said duct andinto said chamber where the matter is deposited; the pressure side ofsaid suction means discharging screened air drawn from said chamberthrough said screening means to a diffuser duct have duct walls whichdiverge towards the outlet end thereof, for discharge to atmosphere; thelength of said diffuser duct being at least thirty centimeters, the ductbeing of rectangular cross-sectional shape, all four walls of the ductdiverging and the included angle between opposite sides of the ductbeing from three degrees to fifteen degrees.
 20. A cleaning vehiclecomprising:a rigid self-propelled vehicle body; ground wheels to supportsaid vehicle body and including one or more steerable wheels mounted forsteering movement relative to the adjacent structure of said vehiclebody; control means to control said steerable wheels; matter removalmeans positionable in working relation to a surface to be cleaned toremove matter therefrom, said matter removal means comprising brush gearand a matter inlet suction nozzle; said brush gear being pivotallymounted on said vehicle body for lateral movement inwards and outwardsrelative to the travel direction of the vehicle about an axis relativeto the adjacent structure of said vehicle body during use; a chambercarried by said vehicle body to receive matter removed by said matterremoval means in a cleaning operation; a duct connecting said chamberwith said inlet nozzle and suction means having its suction sideconnected to said chamber through screening means to draw air from saidchamber thereby lowering the pressure therein and causing air and matterto be drawn through said inlet nozzle and through said duct and intosaid chamber where the matter is deposited; the pressure side of saidsuction means discharging screened air drawn from said chamber throughsaid screening means to a diffuser duct having duct walls which divergetowards the outlet and thereof, for discharge to atmosphere; the lengthof said diffuser duct being at least thirty centimeters and the ductbeing of rectangular cross-sectional shape, two walls thereof divergingand the included angle between said diverging sides being from fivedegrees to twenty degrees.
 21. A cleaning vehicle comprising:a rigidself-propelled vehicle body; ground wheels to support said vehicle bodyand including one or more steerable wheels mounted for steering movementrelative to the adjacent structure of said vehicle body; control meansto control said steerable wheels; matter removal means positionable inworking relation to a surface to be cleaned to remove matter therefrom,said matter removal means comprising a brush and a matter inlet suctionnozzle; said brush being pivotally connected by at least one mountingarm to said vehicle body for lateral movement inwards and outwardsrelative to the travel direction of the vehicle about an axis relativeto the adjacent structure of said vehicle body during use; andconnecting means for connecting said brush to said mounting arm, whichconnecting means includes a hollow body forming part of the load bearingsupport structure for said brush and serving as a housing for the drivemeans therefore, said hollow body having connection means for directload-bearing connection to said mounting arm and being formed as asingle hollow structure made of a polymeric material and serving as aflexible and/or resilient impact device for collisions with streetfurniture and the like.